Refrigeration apparatus



Jan. 16, 1934. MlLLER 1,943,616

REFRIGERAT I ON- APPARATUS Filed June 11, 1930. 4'Shests-Sheet l I 2.9 /7 i 22 4a 3 4 I V/IIIIIIIIIIIA I/IIIIIIIIIII/I a a M a M i a ./a il a g d i F229 25 7 V 3-3226 0 OLIC I gwuento u Jan. 16, 1934. E. B. MILLER REFRIGERATION APPARATUS 4 Sheets-Sheet 2 Filed June 11, 1930 w m u M E. B. MILLER 1,943,616

Jan. 16, 1934.

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3449 Bid gnuewioz v M/ZM Jan. 16, 1934. E. B. MILLER REFRIGERATION APPARATUS Filed June 11, 1930 4 Sheets-Sheet 4 Patented Jan. 16, 1934 1 943 1 UNITED STATES PATENT OFFICE,

REFRIGERATION APPARATUS Ernest B. Miller, Baltimore, Md., assignor, by

inesne assignments, to Chester F. Hockley, Receiver for The Silica Gel Corporation, Baltimore, Md., a corporation of Maryland Application June 11, 1930. Serial No. 460,520

25 Claims. 62-5) This invention relates to refrigeration ap- Figure 8 is a horizontal section through the paratus and particularly to adsorber units and wick compartment of one of the burners 01 control mechanism for such apparatus. Figures 6 and '7 taken on line 8-8 of Figure 9;

It is a general object of the present invention Figure 9 is a vertical section taken on line 9-9 to provide novel and improved adsorption reof Figure 8; and 0 frigeration apparatus. Figure 10 is a diagram of the electric circuits More particularly it is an object of the invenand control apparatus for refrigeration aption to provide means whereby a pair of adsorbers paratus constructed according to Figures 6 to 9, is alternately heated from a single source of heat inclusive, but applicable to other modifications. l0 and controlled in accordance with the refrigera- This invention discloses improvements in and 05 tion demand. modifications of the invention disclosed in my One of the important features of the invention copending application, Serial No. 347,032, filed resides in the arrangement of a pair of adsorbers March 14, 1929, wherein a system of and appain adjacent casings together with means to alterratus for adsorption refrigeration is disclosed, nately direct heat from a single source over the such as illustrated diagrammatically in Figure adsorbers and at the same time to provide a flow 1 of the present drawings. In that figure there of cooling fluid over the adsorber not being heated. is shown at 10 a compartment, such, for instance, Another feature of the invention resides in a as a food storage compartment suitably enclosed novel arrangement and construction of oil burin insulating walls 11 and provided with any 0 ners and control mechanism therefor for heating convenient form of cooling unit or evaporator the adsorbers. 12. Any type of evaporator can be used, but Still another feature of the invention resides there is shown the flooded type in which coils in control apparatus for refrigeration devices of or pipes 13 are filled with a suitable liquid rethe type described wherein the cyclic operation frigerant, such, for instance, as sulphur dioxide, is so controlled that. irrespective of the refrigand maintained full by means of the valve and so eration demand existing, each phase of the cycle float mechanism 14 in the tank 15 from which is permitted to terminate before the process is the pipes 13 lead. A vapor pipe 16 extends from stopped by temperature responsive means or other the tank 15 to the check valve housing 1'7 condemand indication. v nected by means of the pipe 18 to one or more Other and further'objects and featuresof the adsorbers 19. These adsorbers are conveniently 5 invention will be apparent to those skilled in the formed from a plurality of steel tubes 20 conart upon a consideration of the accompanying nected to headers and subheaders 21 joined to drawings and following specification wherein are the vapor pipe 18. The vertical tubes are filled disclosed several exemplary embodiments of the with a suitable adsorbent material, suc r i 35 invention, with the understanding that such stanc asaha d, p us substance like s a changes and modifications may be made therein is ad o t material has an affinity 0 as fall within the scope of the appended claims the apo of t e re ri erant, and, upon adsorbwithout departing from the spirit of the ining, it low s t p ur ab the q d in vention. the evaporator which then boils by taking up K) In said drawings: heat from the chamber 10, thus cooling it. The

Figure l is a schematic showing of an adsorp- Vapor On s W y 130 the adsorber Passes through tion refrigeration system to which the present the check v v 22 which p v t any etur invention may be applied; from the adsorber direct to the evaporator.

Figure 2 is a vertical section through an ad- When the adsorbent s u ed, r n arly so, 45 sorber unit comprising a pair of adsorbers and it mu t be res ored to s normal condition for associated apparatus; reuse. This restoring, which is termed acti- Figure 3 is a side elevation partially in vertical vat n s t d by app y at, r nstan e. section of the device of Figure 2; from a gas or oil burner 23, to the outside of Figure 4 is a partial View simnar t Figure 2 the tubes which are housed in a suitable jacket 50 showing a different burner arrangement; 24 connected to a stack 25. The liquid in the Figure 5 is a side elevation of the burner arpores of the adsorbent is driven off as a vapor 'rangement of Figure 4; and passes through the check valve 26 into the Figures 6 and '7 are views similar to Figures pipe 2'? leading to a suitable condenser 28, which 4 and 5 but of a further modified burner conliquefies the vapor which then collects in the 55 struction; receiver 29, which returns it by gravity, or by the differences in pressure existing between the adsorber and the evaporator, through the pipe 30 into the tank 15 under the control of the valve 1 1.

This form of apparatus is shown in the prior application and operates cyclically, as can be understood from the brief description above. Sometimes it is desirable to have substantially continuous adsorption, and this can be effected by providing a, plurality of adsorbers so that one or more can be adsorbing while others are being activated-andcooled. The present invention provides means whereby two adsorbers, or more if desired, can be used, and heated from a single source of heat.

Referring now to Figures 2 and 3, showing only the adsorber units, it will be seen that there are two adsorbers 300, arranged in a single housing. preferably formed of heat insulating material and provided with a central partition 301 dividing it into two vertical compartments or fiues, in each of which one adsorber is arranged. The top of the whole casing converges as at 302 to the inlet of the eduction fan 303, suitably driven as by an electric motor 304. If desired, this motor may drive a fan for cooling the condenser as in the prior application, but this forms no part of the present invention. 4

For heating the adsorbers, a plurality of burners 305 is shown, arranged beneath the compartments and the partition 301. For certain purposes it may be desired to use a liquid fuel, and so the burners 305 have been shown as of the oil burning type, all supplied with fuel through the pipe 306 from any convenient source, the flow of which is regulated by a valve 307. In order to provide a means for maintaining a substantially constant temperature in the adsorber compartments, a linkage 308 connects the operating member of the valve to a thermo-responsive element 309 arranged above the burners. Under the control of this element the valve serves to regulate the rate of flow of oil and hence the amount of heat supplied to the burners which, in this particular modification, are assumed to burn continuously.

In order to heat but one adsorber at a time while the other is adsorbing, and to supply cold air to the one on the adsorption phase, the heat from the burners 305 is deflected to one or the other of the flues formed by the partition 301 by means of a pair of lower dampers 310 and a single upper damper 311, each of which cooperates, respectively, with the outer walls of the adsorber casing and the central partition.

The lower dampers are pivoted at 312 each substantially beneath the center of the flue above it and near the level of the tops of the burners. The lower dampers are connected by means of a link 313 for movement in unison, and, when in one position, one cooperates with the nearest wall of the adsorber casing and the other with the central partition. 7 When in the reverse position, the opposite conditions exist. When in the position shown in Figure 2, it will be seen that heat will pass from the burners into the left-hand flue under the action of a natural draft and the fan, and, under the action of the fan, air will enter through the passage 319 and into the other flue to cool the adsorber which is on the adsorption phase and remove therefrom the latent heat of adsorption.

The upper damper 311 is pivoted to the partition between the fiues and is connected by a linkage 314 to move in unison with the lower damper and to be substantially parallel to that damper which engages the side wall of the adsorber casing. When in the position shown, it substantially closes oil the flue which receives heat from the burners except for a small passage 315 which permits the fan to cause a circulation therethrough. This prevents too rapid a flow of air over the adsorber being heated and permits a better transfer of heat while at the same time opening wide the passage above the other adsorber for a rapid flow of cooling air.

The dampers are shifted, in this modification, at definite intervals by the mechanism 316 driven in any convenient manner from a constant speed shaft, such as the shaft 317 of the motor 314. At the end of a given number of revolutions, the dampers are shifted by the mechanism 316 and the linkage 318 connected to the linkage 314 so that the adsorber which has just been activated is placed on the adsorption phase, and vice versa. This form of device is extremely simple in construction and, since it requires no automatic controls, is low in cost and, for certain installations, is very satisfactory.

In the device shown in Figures 4 and 5, the construction of the adsorbers and the damper arrangement andfan may be similar to that just described in connection with Figures 2 and 3, but the oil burner arrangement and control are different. Here the burners 320 are of the type us- 165 ing an adjustable wick which can be raised or lowered to regulate the amount of heat given off by the burners. Fuel is delivered from the tank 321 to the float valve damper 322 which, in a well-known manner, maintains the oil at a proper, constant level in the wick reservoirs 323. Each wick is under the control of a pinion 324, on a short horizontal shaft 324, which drives the rack 325 which raises or lowers the wick in a conventional manner. Each shaft 324' carries a second pinion 326, and all of these pinions 326 ccoperate with the long rack 326' which can be moved along its horizontal axis to raise or lower all of the wicks simultaneously.

Movement of the rack 326 is effected by means of a so-called half-revolution motor 327 which, when supplied with current under certain conditions, moves its shaft 328 a half revolution and stops until the next application of current, when another half revolution is made. This causes the crank 328 linked to the rack 326 to raise or lower the wicks. The motor may be under the control of a thermal element, such as 50 in Figure 1, in the cooled compartment so that, when sufiicient refrigeration is obtained, the motor 327 130 is so connected as to turn down all of the wicks and thus stop activation without actually putting out the flame.

Upon a requirement for more refrigeration, as indicated by a movement of the thermal element 135 50, the motor is started, and the wicks turned up so that the flames increase and heat is supplied to the adsorber selected by the position of the dampers. If the fan motor is arranged to be stopped when the wicks are turned down, then the cyclic operation will not be upset. However, a preferred form of control would be an adaptation of the type described in connection with Figure 10.

Figures 6 and '7 show a form of adsorber ar- 74% rangement similar generally to that in Figures 2 to 5, inclusive, but having a diiierent type of burner and control mechanism. In this construction each of the burners 330 has a wick reservoir 331 shown in Figures 8 and 9 to be in the form 5:

of a hollow annular chamber supplied with oil through a feed pipe 332 to feed the asbestos wick 333 arranged therein to form just slightly less than a complete ring. The gap between the end of the wick accommodates the vertical metal tube 334 which passes through the annulus and holds the continuously burning pilot wick 335 so that its upper end, where it projects slightly above the tube, is sufficiently close to the ends of the main wick to light the main wick when it is supplied with oil.

The pilot wick extends down to the level 336 in the pipe 334 which is much below the bottom of the main wick chamber. The pilot wick chamber is connected to the same oil supply pipe 337 to which the main wick chamber 331 is connected. This pipe 337 bends upwardly as at 338 and is topped by a flared end or funnel 339 adapted to receive oil from the pipe 340 through a manually adjustable valve 341 which receives its oil from an oil reservoir at 342 by means of a suitable electric pump 343, such as the type some times used for supplying gasoline to motor cars and engines for watercraft. Such a pump as that known by the trade name Autopulse" is satisfactory, for this pump is of such construction that it pumps only at the speed required to deliver fuel against a few ounces of pressure, and hence its speed of operation can be controlled by regulating the valve 341.

Oil is maintained at a constant level in the wick reservoirs 331 by means of the overflow pipe 344 connected to the pipe 348 below the funnel and at the proper level to maintain the desired level of fuel in the reservoirs 331. It discharges into the funnel 345 connected to a pipe which returns excess fuel to the tank 342. This insures a constant level of oil during the burning of the burners and thus a constant size of flame and a substantially constant flow of heat.

In order to extinguish the flames from the main wicks, the by-pass valve 346 is opened. This valve is connected to the pipe 338 below the level of the bottoms of the wick chambers 331 so that, when it is opened, oil may all drain to the level 347, thus emptying the chambers 331 so that after a few moments the oil in the wicks is burned out and the flames extinguished.

This lowering of the level of the oil in the main wick chamber supply pipe does not lower it below the bottom of the pilot wicks, which thus remain lighted so that, when oil is again delivered to the main wick chambers, the flames will be rekindled from the pilot wicks. In accordance with the control apparatus to be later described, the pump 343 is arranged to be shut off when the valve 346 is opened, so a reservoir 348, connected to the oil supply pipe 337 and arranged below the level of the bottom of the chambers 331, is provided to supply oil to the pilot wicks. It is vented as at 351 and is of sufiicient capacity to supply the pilot wicks for any normal length of time during which the main wicks may be extinguished. Reservoir 348 is replenished as soon as the pump 343 is started up.

By providing the two funnels 339 and 345, all of the burners and their valve 346 can be arranged on a truck 349 supported by rollers 350 from a suitable stationary track in the base of the adsorber casing. In this way all of the burners can be withdrawn for cleaning and adjusting without disturbing any piping.

The valve 346 which drains oil from the main wick reservoirs is preferably solenoid operated and so constructed that the valve is closed when the current is turned on so that the main burncessation of current flow. This provides a safe- .ty feature so that, if current is shut off for any reason, the main burners will be put out. This, of course, prevents burning of the burners when the fan is not running. Where gas is available, it will be a simple matter to substitute gas burners for the oil burners with an elimination of certain of the apparatus. In this case constantly burning pilot burners will be provided, and the valve 346 will become a solenoid operated gas valve which'closes when the current shuts off.

In Figure 10 there is shown control mechanism for refrigeration apparatus susceptible of application to any of the forms of device shown including that described in connection with the use of gas burners. In this diagram the fan motor is seen at 304 and the oil pump at 343, but this oil pump will be eliminated when gas burners are used. At 346 is seen the oil or gas valve and at 367 a half-revolution motor for operating the dampers. This motor is of the type described in connection with Figures 4 and 5 but, instead of being connected to operate the wicks, is connected to shift the dampers, as shown in the application referred to.

A source of current supply 352 is arranged to have one side of the line connected to the wire 353 and thus to one terminal of the half-revolution motor 367. This wire 353 is also connected to one terminal of a mercury switch 354 operated either in accordance with the temperature in the cooled compartment or by the pressure in the evaporator. It is so arranged that, upon the obtaining of a sufliciently low temperature in the refrigerating compartment, the switch 354 is tilted to open the circuit. This switch is in control of the motor 304 for operating the-fan. The other side of the motor is connected by means of the wire 355 to the other side of the line 352. By this connection it will be seen that, when sufficient refrigeration is obtained, the opening of the switch 354 stops the operation of the motor 304. The oil pump 343, the oil valve 346, and an electric clock 359 also are connected between the switch 354 and the line 355 so that they too will be stopped in case the switch 354 is opened.

The electric clock is any one of the well-known types of synchronously driven electric clocks serving to drive the shaft 357 at a constant speed with, say, one revolution per hour or at any other desired speed to control activation in accordance with the requirements. This motor drives three cams 358, 361, and 363. The cam 358 is a twolobe one, controlling the tilting of an electric switch 356 which is shunted around the switch 354 and which is opened for short intervals twice a revolution of the clock shaft.

A mercury switch 362 is controlled by the twolobe cam 361, and this cam regulates the oil or gas valve 346 and the oil pump, if one is provided, to permit supply of fuel to the burners over a short part of a half revolution of the shaft. This permits activation for, ,say, one fourth of a half revolution of the shaft and adsorption during the other three quarters. The process is repeated for the other half revolution and other adsorber.

The cam 363 controls the four-contact mercury switch 364 which is associated with the switching mechanism 365 on the shaft of the half revolution motor 367 in such a manner that, when the mercury moves to one end of the switch, the motor makes a half revolution and stops and, when the switch is tilted to move the mercury to the other end. the motor makes another half revolution and stops. This insures that the dampers, during a half revolution of the clock shaft, permit one adsorber to be activated and duringthe other half revolution permit the other adsorber to be activated. This cam 363 is so synchronized with the cam 361 that fuel is supplied to the burners just as the dampers are thrown open so that they burn about one fourth of the period in which the dampers are in this position.

In order that the automatic control switch 354.- may not be able to turn off the fuel and stop the motor 304 and clock 359 in the middle of an activation period, the switch 356 is arranged in shunt thereto so that, if sumcient refrigeration occurs sometime intermediate the starting and normal'stopping of the burners by means of the cam 361, the circuit will be maintained closed by means of the switch 356 until the proper time for the phase of the cycle to be normally terminated. Even though the burning be stopped by the cam 361, still the cycle cannot be interrupted until the switch 356 is tilted so that at least a normal period of adsorption is given to the other adsorber.

It will be noted that, by virtue of the arrangement, the switch 354. cannot stop activation unless the phase of the cycle which has previously been started is terminated. Upon this termination and a condition of sumcient refrigeration, the clock will be stopped, the fuel having already been turned off. This stops all operation until refrigeration is again required, as indicated by a closing of the switch 354, which then starts up everything in its proper relationship to the new phase of the cycle which is to start.

It will be seen that by the arrangement just described the damper operation and the fuel valve operation are synchronized and properly timed and that partial activations are prevented. By stopping the fan as well as the clock, excess refrigeration is prevented, for, should the clock be stopped at the end of a cycle, the whole capacity of that adsorber just activated would then be available for further refrigeration, but, in the absence of cooling air, the rate of adsorption will be materially slowed up so'that excess refrigeration will not be produced. It will be noted that the lobes on the cam 358 are quite short so that, after its switch has been opened to permit the various devices under its control to stop, in case switch 354 is opened, it will be closed again very shortly after the' clock goes into operation upon a subsequent closing of the switch 354 and thus lock the next phase of the cycle for completion.

Safety devices may be applied to this system as in the prior application. The mercury switch 368 in circuit with the clock, fuel valve, and pump is opened upon excess pressure in the system and the switch 369 in the same circuit upon excess temperature in the adsorbers. Where gas is used as the fuel, a thermo-responsive element operates the switch 370 to shut down the Whole system in case the pilot burner oes out.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a refrigeration device, in combination, a plurality of adsorbers, a casing housing said adsorbers and having means separating them, a burner in said casing beneath said means to heat said adsorbers, and means to direct the heat ea ers therefrom to one adsorber at a time, said last mentioned means deflecting air. for cooling over another adsorber.

2. In a refrigeration device, in combination, a pair of adsorbers, a casing housing said adsorbers and having a partition dividing it into two sub= stantially vertical flues each containing one ad= sorher, a burner beneath the open bottom of said casing directly under said partition, and damper means to direct heat to and shut ofi unheated air from one of the adsorber flues at a time.

3. In a refrigeration device, in combination, a pair of adsorbers, a casing housing said adsorbers and having a partition dividing it into two sub stantially vertical flues each containing one ad sorber, a burner beneath the open bottom of casing directly under said partition, and damper means to direct heat to and shut ofi unheated air from one of the adsorber flues at a time, said damper means also cutting on heat and opeg an air passage to the other adsorber flue.

i. In a refrigeration device, in combination, a pair of adsorbers, a casing housing said adsorber-s and having a partition dividing it into two substantially vertical flues each containing one adsorber, a heater beneath the open bottom of said casing, damper means to direct heat and shut ofi unheated air from one of the adsorber flues at a time, and means to partially close the top of the flue receiving heat.

5. In a refrigeration device, in combination, a pair of adsorbers, a casing housing said adsorbers and having a partition dividing it into two substantially vertical flues each containing one adsorber, a heater beneath the open bottom of said casing, damper means to direct heat and shut ofi unheated air from one of the adsorber flues at a time, said damper means. also cutting ofi heat and opening an air passage to the other adsorber flue, and damper means at the top of said flues movable with said first mentioned damper means to restrict the passage of heat from the flue open to the heater.

6. An adsorber unit for refrigeration comprising a pair of casings forming parallel fiues, an eduction duct associated with adjacent ends of said fiues, means to draw air through said flues and duct, an adsorber in each flue, means to supply heat at the opposite ends of said flues, means to selectively close one flue to heat and open it to atmosphere and said duct and open the other flue to heat, close it to atmosphere and partially close it to said duct.

'7. An adsorber unit for refrigeration comprising, in combination, a pair of adsorbers, a casing for each adsorber forming a flue, said flues being parallel, adjacent and open at one end to the atmosphere, the opposite ends of said flues being connected to a single duct, suction means connected to said duct, a source of heat at the open ends of said flues, a damper at the duct end of said flues adapted to be positioned to partially close one flue and fully open the other to the duct, a pair of connected dampers at the open ends of said flues adapted to close one flue to atmosphere and deflect heat from the heater thereto and to open the other to atmosphere and close it to heat.

8. An adsorber unit comprising in combination, a pair of adjacent casings forming flues open at one end, a duct jointing the other ends of said flues, a suction device connected to said duct, an adsorber in each flue, a source of heat, means to direct heat into either flue at the end opposite to said duct and to open the other to atmosphere,

Mill) means to substantially close the heated flue to said duct and open the other wide and mechanism connecting said means to operate in unison.

9. An adsorber unit comprising in combination, a pair of adjacent casings forming flues open at one end, a duct jointing the other ends of said flues, a suction device connected to said duct, an adsorber in each flue, a source of heat, means to direct heat into either flue at the end opposite to said duct and to open the other to atmosphere, means to substantially close the heated flue to said duct and open'the other wide, mechanism connecting said means to operate in unison and means to operate said mechanism periodically to reverse the conditions of the flues.

10. An adsorber unit comprising in combination, a pair of adjacent casings forming flues open at one end, a duct jointing the other ends of said fiues, a suction device connected to said duct, a motor to drive said suction device constantly, an absorber in each flue, a source of heat, means to direct heat into either flue at the end opposite to said duct and to open the other to atmosphere, means to substantially close the heated flue to said duct and openthe other wide and mechanism connecting said means to operate in unison and means associating said motor and mechanism to periodically reverse the conditions of the flues.

11. An adsorber unit comprising in combination, a pair of flues, an eduction duct, damper means to selectively connect said fiues to said duct, a source of heat, damper means to selectively associate said flues and source of heat and means to cause said damper means to operate in unison.

12. In a refrigeration unit, in combination, an adsorber, a motor driven fan therefor, a burner to heat said adsorber, a valve for said burner biased to shut off the burner, electric means to ovecome said bias, a source of current, a circuit connecting said source to said motor and said valve operating means, time controlled means to open and close the circuit to the valve operating means, a temperature controlled device to open the circuit to both the motor and valve operating means, a circuit normally shunting the temperature controlled means and a switch in said shunt circuit actuated by said time controlled means to open only when a change in condition of the valve operating means is effected.

13. In a refrigeration unit, in combination, an adsorber, a heater for said adsorber, an electric control for said heater, a source of current, a circuit connecting said source and control, a

timing device, means actuated thereby to periodically open and close said circuit, a temperature responsive means effective to open said circuit, a shunt for said temperature responsive means to maintain the circuit shut and means actuated by said timing device to open the shunt circuit at the beginning of each period of opening and closing of said heater control circuit.

14. In a refrigeration unit, in combination, an adsorber, a heater for said adsorber, an electric control for said heater, a source of current, a circuit connecting said source and control, a timing device driven from said. source of current, means actuated thereby to periodically open and close said circuit, a temperature responsive means effective to open said circuit and stop the timing device, a shunt for said temperature responsive means to maintain the circuit shut and means actuated by said timing device to open the shunt circuit at the beginning of each period .electric control for said damper, a timing device driven from said source of current, means actuated thereby to periodically open and close said circuit, a temperature responsive means effective to open said circuit and stopthe timing device, a shunt for said temperature responsive means to maintain the circuit shut, means actuated by said timing device to open the shunt circuit at the beginning of each period of opening and closing of said heater control circuit and means actuated by said timing device to actuate the damper control to reverse the damper in timed relation to the heater control.

16. In a refrigeration unit, in combination, an adsorber, a motor driven fan therefor, a heater for said adsorber, a damper associating said adsorber and fan, an electric control for said heater, a source of current, a circuit connecting said source and said control, a circuit connecting said source and said motor, an electric control for said damper connected to said source, a timing device driven from said source of current, means actuated thereby to periodically open and close the heater control circuit, a temperature responsive circuit breaker effective to open the motor, heater control and timing device circuits, a shunt for the circuit breaker, means actuated by the timing device to open the shunt circuit prior to each change in the heater control circuit and means actuated by said timing device to actuate the damper control to reverse the damper in timed relation to the heater control changes.

17. In a refrigeration unit, in combination, an adsorber, a liquid fuel burner therefor comprising a wick chamber containing a wick, a source of fuel, means to maintain a substantially constant level of fuel in said chamber and means dependent on the state of refrigeration developed to drain the fuel from said chamber.

18. In a refrigeration unit, in combination, an adsorber a liquid fuel burner therefor comprising a chamber, a source of fuel, means to maintain a substantially constant level of fuel in said chamber and means dependent on the state of refrigeration developed to drain the fuel from said chamber.

19. In a refrigeration unit, in combination, an adsorber, a main fuel burner having a chamber, a pilot burner having a chamber adjacent thereto and extending to a lower level, a source of liquid fuel, means to conduct fuel from said source to both chambers, means under control of the state of refrigeration to lower the level of the fuel below that of the main burner chamber and stop delivery of fuel and an auxiliary reservoir below the level of the main burner chamber and associated with the pilot burner chamber.

20. In a refrigeration unit, in combination, an adsorber, an evaporator associated theerwith, a main fuel burner having a chamber, a wick therein, a pilot burner having a chamber, a wick therein in cooperating relation to the main burner wick, said pilot burner chamber and wick extending below the lowest level of the main burner wick, a fuel tank below the level of the chambers, means to supply fuel to a constant level in said chambers, means responsive to the state of said evaporator to return fuel to said tank from the main chamber to lower the level below the main wick but not below the pilot wlclr and an auxill= ary fuel reservoir associated with the pilot cham= her.

21. In a refrigeration unit, in combination, an adsorber, an evaporator associated therewith, a main fuel burner having a chamber, a wick therein, a pilot burner having a chamber, a wick therein in cooperating relation to the main burner wick, said pilot burner chamber and wick extending below the lowest level of the main burner wick, a fuel tank below the level of the chambers, means to supply fuel to a constant level in said chambers, means responsive to the state of said evaporator to return fuel to said tank from the main chamber to lower the level below the main wick but not below the pilot wick and an auxiliary fuel reservoir associated with the pilot chamber, said fuel supply means filling said reservoir when the high level is supplied and said return means being above the level of said auxiliary fuel reservoir.

22. In a refrigeration unit, in combination, an adsorber, a casing therefor, a burner compartment adjacent said casing, a liqud fuel burner unit slidably mounted in said compartment, a fuel pipe for said unit having an enlarged end open at the top, a fuel tank, a delivery pipe extending therefrom and having its end in position to deliver fuel into said fuel pipe, means to deliver to said delivery pipe an excess of fuel over that required, an overflow pipe associated with said fuel pipe to maintain aproper fuel levelfor said burner unit and having an open discharge end and a return pipe to said tank having an enlarged upper end in a position to receive said overflow, there being no direct connection between said unit and tank whereby the unit can be removed without disconnecting any pipes.

23. In a refrigeration unit, in combination, an adsorber, an evaporator associated therewith, a

burner for said adsorber, a fuel chamber in said burner, a feed pipe for'said chamber, a fuel tank, means to deliver from said tank an excess of fuel, an overflow pipe adapted to return the excess to the tank and maintain a constant level in said chamber, a second overflow pipe at such a level as to empty the chamber, a valve in said second overflow pipe and means dependent on the state of the evaporator to exercise control over said valve.

24;. In a refrigeration unit, in combination, an adsorber, an evaporator cooperating therewith, a fuel burner for said adsorber, and means responsive to temperature to control ,the flame of said burner to maintain a substantially constant temperature surrounding the adsorber.

25. In a refrigeration unit, in combination, an adsorber, an evaporator cooperating therewith, a

fuel burner for said adsorber, and means responsive to temperature adjacent said adsorber to regulate the size of the flame from said burner.

ERNEST B. MHLER. 

